The census is conducted every five years to gather information on populations for electoral purposes and guide government spending on new infrastructure, community services and facilities such as schools, hospitals and roads.

This is the 16th census taken in Australia over the past 100 years with about 9.8 million households surveyed on August 9 last year.

The data revealed Australia's population rose to 21,507,719, up almost two million - or more than 8 per cent - in the past five years, and the median age of the growing population rose from 37 in 2006 to 38 when the census was counted last year.

The United Kingdom stood as the leading country of birth for the overseas-born population at 20.8 per cent and was followed by New Zealand (9.1 per cent), China (6.0 per cent) and India (5.6 per cent).

Of the 21.5 million, 24.6 per cent of them were born overseas, up from 22.2 per cent in 2006, while 43.1 per cent of people had at least one parent who migrated here.

While the UK was still the leading country of birth, New Zealand, China and India followed closely behind, the data said adding Hinduism experienced largest proportional growth of the three most common non-Christian religious affiliations.

People of Indian origin have seen the largest growth increase at more than 14 per cent since 2006, or up almost 150,000.

The increase in people speaking Punjabi has boomed more than 200 per cent, the data revealed.

In Victoria, the proportion of people born overseas climbed from 23.7 per cent in 2006 to 26.2 per cent in 2011, with India now the third most reported country of birth in Victoria, making up 2.1 per cent of the population.

"Multiculturalism plays a big part in who we are as a nation and we thank all community groups for their participation in the census, and helping to create a brighter future for all Australians," Henderson said.